Superfamily PSALIDOPODOIDA. 



Family Psalidopodidae. 

 Psalidopus W.-Mas. 



This genus, the only one of the remarkable family of Psalidopodidae, is only represented 

 by two species, which were discovered during the Season 1890 — 91 by H. M. Indian Marine 

 Survey Steamer " Investigator" in the Andaman and Arabian Seas. Psalidopus Huxlcyi W.-Mas. 

 was until at present only known by a single adult female, taken at a depth of 490 fathoms 

 in the Andaman Sea, 7 1 /., miles east of N. Cinque Island. Of the other form, Psalidopus spini- 

 ventris W.-Mas., both the male and the female are known: five specimens have been obtained 

 in the Andaman Sea at 405 and 500 fathoms, in the Arabian Sea, in the neighbourhood of 

 the Laccadives, at 636 and off Cape Comorin at 480 fathoms. 



The Psalidopodidae are apparently very rare animals, a suggestion conhrmed by the fact 

 that the "Siboga" has only obtained one single individual. 



1. Psalidopus Huxlcyi W.-Mas. PI. XVI, Fig. 47, 4.7a. 



Psalidopus Huxlcyi J. YVood-Mason, Ann. Mag. Nat. Hist, April 1892, p. 273, PI. XIV. 



figs. 1, 2, 7. 

 Psalidopus Huxleyi A. Alcock, A descript. Catal. Indian Deep-Sea Crustacea, Calcutta 1901, 



p. 112. 

 Illustrations of the Zoology of the Investigator, Crustacea, PI. LI, figs. 5, $a — b. 



Stat. 300. January 30, 1900. lO°48'.6S., I23°23'.i E. Off the south coast of Rotti. 918 m. 

 Bottom fine grey mud. 1 adult female without eggs. 



As far as I am aware, this is the second specimen of this species, which has been 

 discovered; it is therefore a capture of great importance, though the discovery of the male should 

 have been still more interesting. Our specimen very well agrees with the quoted descriptions 

 and figures and shows about the same size. The carapace, indeed, from supra-orbital to posterior 

 margin proves to be 28,5 mm. long, the rostrum 52 mm., but the abdomen is 72 or 73 mm. 

 long from the middle of the anterior margin of first tergum to tip of telson, instead of 63 mm. 

 in Wüod-Masox's specimen. In the first description of 1892 both species are distinguished, 

 besides by the thoracic and abdominal sterna being unarmed or not, by the existence in Psalid. 



S1BOGA-EXPEDITIE XXXIX,; 3 . 24 



